JPH0622677B2 - Hydrogenation catalyst - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a catalyst comprising a copper-iron-aluminum-zinc atom having high activity and high selectivity, which catalyst is used for producing alcohol by hydrogenation of fatty acid ester. .

[Problems to be Solved by Prior Art and Invention]

Higher alcohol is higher fatty acid methyl ester under high temperature,
It is produced by reduction with high pressure hydrogen.

Conventionally, the catalyst used in this reaction is a copper-chromium oxide-based catalyst, and is usually called a copper-chromite catalyst. The manufacturing method has not been much improved from that described in Industrial and Engineering Chemistry Vol. 26, page 878 (1936).

This catalyst has the serious drawback of producing large amounts of hexavalent chromium ions during manufacture. In order to prevent environmental pollution, these heavy metals are collected by an appropriate method, but the final treatment method of the heavy metal sludge generated here has not been established yet.

Copper produced by various methods to solve this problem
Iron-aluminum catalysts have been proposed (JP-A-53-923).
95, JP-A-55-8820, and JP-B-58-50775).

However, although these catalysts are superior in activity, selectivity and durability to the conventional copper-chromite catalysts, the filtration rate is slow when the catalyst is separated from the catalyst-precipitated slurry during the production of the catalyst, which requires a large-scale filtration facility. However, there is a defect that the catalyst is remarkably atomized when the reaction product is withdrawn from a high pressure to a normal pressure through a high pressure valve after the reaction. However, since urea is used as a catalyst precipitant, there is a problem in the manufacturing process such as a large load on urea wastewater and ammonia wastewater treatment resulting from this (Japanese Patent Publication No. 58-50775). ).

[Means for Solving the Problems]

As a result of intensive studies on the problem of suppressing the atomization of the catalyst and the rationalization of the catalyst production process, the inventors have established an industrial production method of a pollution-free catalyst which replaces the copper-chromite catalyst inherent in the problem of environmental pollution. , Aluminum hydroxide or aluminum oxide or a mixture thereof as a carrier, and by using a hydroxide or carbonate of an alkali metal or an alkaline earth metal instead of urea as a precipitant, atomization of the catalyst can be suppressed, Activity, selectivity,
The inventors have found that a catalyst having significantly improved durability and filterability can be obtained, and completed the present invention.

That is, the present invention uses aluminum hydroxide or aluminum oxide or a mixture thereof as a carrier, and Cu, Fe, Al and
The atomic ratio (the atomic ratio of the entire catalyst including the carrier) including Zn is
Cu / Fe / Al = 1 / 0.4 / 2.5 / 0.5 to 5.0, and
The present invention provides a catalyst for alcohol production by hydrogenating a fatty acid ester having Zn / Cu ≦ 1.0.

The copper-iron-aluminum-zinc catalyst of the present invention is produced, for example, by a production method in which the following first step, second step and third step are performed in this order.

(First step) The carrier is suspended in an aqueous medium, and the water-soluble copper salt and the water-soluble iron salt are reacted with the alkaline substance in the suspension to precipitate the copper compound and the iron compound on the surface of the carrier. The process of making.

(Second step) In the suspension obtained in the first step, (i) by reacting a water-soluble aluminum salt with an alkaline substance, or (ii) a water-soluble aluminum salt and a water-soluble copper salt Alternatively, by reacting a water-soluble zinc salt or a mixture thereof with an alkaline substance, selected from the following (a) to (d) on the surface of solid particles present in the suspension obtained in the first step: The compound of claim 1, which is precipitated once or twice or more (in two or more times, in no particular order). However, in this case, the step of precipitating the zinc compound is performed at least once.

(a) Aluminum compound.

(b) Aluminum compounds and copper compounds.

(c) Aluminum compounds and zinc compounds.

(d) Aluminum compounds, copper compounds and zinc compounds.

(Third step) A step of obtaining a precipitate from the suspension obtained in the first step and the second step, washing with water, drying and firing.

The copper-iron-aluminum-zinc-based catalyst according to the present invention has a composition whose atomic ratio (atomic ratio of the entire catalyst including the carrier) is Cu.
/Fe/Al/Zn=1/0.4-2.5/0.5-5.0, and
It is important to be in the range of Zn / Cu ≦ 1.0. When the atomic ratio is out of these ranges, the activity of the obtained catalyst becomes smaller than that of the copper-chromite catalyst and, at the same time, the amount of by-products increases when it is used in the hydrogenation reaction.

Each step of the method for producing a copper-iron-aluminum-zinc catalyst of the present invention will be described below.

First Step The first step in the manufacturing method of the present invention is performed as follows.

First, the water-soluble copper salt and the water-soluble iron salt are Cu / Fe = 1 in atomic ratio.
It is dissolved in water so as to have a ratio of /0.4 to 2.5, and aluminum hydroxide or aluminum oxide or a mixture thereof is suspended in this aqueous solution so that the atomic ratio is Cu / Al = 1 / 0.1 to 3.0. This suspension is heated to 60 to 120 ° C, and an aqueous solution of an alkaline substance in an amount corresponding to the total equivalent number of copper and iron ions is added to the copper compound and the iron compound to form aluminum hydroxide or aluminum oxide or these The mixture is precipitated on the surface of a catalyst carrier.

As the water-soluble copper salt used in the present invention, cupric sulfate,
Examples thereof include cupric chloride and cupric nitrate, and a mixture of these may be used.

The water-soluble iron salt used in the present invention, ferrous chloride,
Examples thereof include ferrous sulfate and ferrous nitrate, and a mixture of these may be used, but ferrous sulfate is optimally used from the economical aspect. It is also possible to use a ferric salt in combination, but care must be taken because excessive addition of the ferric salt deteriorates the catalyst performance, particularly the physical properties of the catalyst.

Examples of the alkaline substance used in the present invention include hydroxides or carbonates of alkali metals or alkaline earth metals. The method of adding the alkaline substance to the suspension is not particularly limited, but in consideration of operability, these alkaline substances are usually added in an aqueous solution.

When an alkali metal or alkaline earth metal hydroxide is used as the alkaline substance, it is desirable to slowly add it in order not to impair the filterability of the precipitation catalyst. In the present invention, it is optimum to use an alkali metal carbonate. Although the concentrations of these alkaline substances can be arbitrarily selected, a high concentration of a precipitant can be used in view of the productivity of the catalyst. For example, in the case of sodium carbonate, an aqueous solution having a concentration of 20 to 23% is suitable.

Aluminum hydroxide or aluminum oxide or a mixture thereof as a carrier used in the first step may be used as it is after prepared in a reaction tank, or may be prepared separately in advance. It is preferable to use those carriers having relatively uniform particle diameters. The average particle size of the carrier is 0.1 to 500 μm, preferably 0.4 to 50 μm.
If the average particle size is below or above this range, both catalytic activity and filterability cannot be simultaneously maintained at the levels desired by the present invention. As a method for preparing a carrier in a reaction vessel, an amount of an aluminum salt used as a carrier, for example, a sulfate, a nitrate, a hydrochloride or the like of an alkali metal hydroxide in an amount equal to or more than the equivalent number of aluminum ions, such as water. After dissolving in an aqueous solution of sodium oxide, or after preparing an aqueous solution of sodium aluminate in an amount to be used as a carrier, dilute sulfuric acid or a part of aluminum salt is made into an aqueous solution at a temperature of 60 ° C or higher and added dropwise for neutralization. There is a way. In the case of this method, the first step can be continuously performed by charging a copper salt and an iron salt into this slurry without purifying the formed precipitate. When a carrier having uniform physical properties is used, a catalyst with more stable properties can be produced. Therefore, it is more advantageous to use a carrier having uniform physical properties for production on an industrial scale.

Second Step The second step in the manufacturing method of the present invention is performed as follows.

That is, (a) Water-soluble aluminum salt (however, the amount of Al in this case is Cu / Al in atomic ratio to the water-soluble copper salt used in the first step).
= 1 / 0.1 to 3.0, preferably 1 / 0.5 to 1.5. ) Aqueous solution, in order to further improve the activity and selectivity in the hydrogen reduction reaction, a water-soluble zinc salt, or a water-soluble copper salt and a water-soluble zinc salt to the water-soluble aluminum salt used in the aqueous solution Al / Cu = 1/0 in atomic ratio
1 and an aqueous solution that is present so that Zn / Al ≦ 0.5, and the total equivalent number of aluminum ions and zinc ions described in (b) (a), or when using a water-soluble copper salt, And an amount of an alkaline substance equivalent to the total number of copper ions are added dropwise, and the aluminum compound and zinc compound, or if necessary, the copper compound is precipitated while maintaining the suspension temperature at 60 to 100 ° C. By doing. When the reaction is carried out at a suspension temperature outside this range, the desired activity and selectivity of the resulting catalyst cannot be obtained.

Examples of the water-soluble aluminum salt described in (a) above include aluminum sulfate, aluminum chloride, aluminum nitrate, and various alums, among which aluminum sulfate is most suitable. Moreover, you may use these mixtures.

Examples of the water-soluble copper salt described above include those described in the first step. Further, examples of the water-soluble zinc salt described above include zinc sulfate, zinc chloride, zinc nitrate, etc., but zinc sulfate is most preferable from the economical aspect.

Examples of the alkaline substance described in (b) above include the alkaline substance used in the first step as well. The addition method is preferably an aqueous solution from the viewpoint of operability. The concentration is not particularly limited, but from the economical aspect
It is preferable to use an aqueous solution of about 20% by weight.

In order to prevent a sudden change in the pH of the suspension, the alkaline substance may be added to the suspension simultaneously with the aqueous solution described in (a) and the alkaline substance or its aqueous solution described in (b). preferable.

When a water-soluble salt other than the water-soluble aluminum salt is used, the second step can be performed in one step or in two or more steps.

An example of the embodiment of the second step is as follows. However, in the second step, the following steps are selected so that the step of precipitating the zinc compound is performed at least once.

 Only the aluminum compound is precipitated.

An aluminum compound and a copper compound are simultaneously precipitated.

An aluminum compound and a zinc compound are simultaneously precipitated.

The aluminum compound and the copper compound are simultaneously precipitated in the first step, and then the aluminum compound and the zinc compound are simultaneously precipitated in the second step.

The aluminum compound and the copper compound are simultaneously precipitated in the first stage, and then the aluminum compound is precipitated in the second stage.

The aluminum compound and the zinc compound are simultaneously precipitated in the first stage, and then the aluminum compound and the copper compound are simultaneously precipitated in the second stage.

The aluminum compound and the zinc compound are simultaneously precipitated in the first stage, and then the aluminum compound is precipitated in the second stage.

The aluminum compound, copper compound and zinc compound are simultaneously precipitated.

The combination of these steps is repeated a plurality of times.

The pH of the suspension obtained by the above-mentioned method is adjusted to 7.0 or more, and then aging is performed for 0 to 8 hours.

Third Step The third step in the manufacturing method of the present invention is performed as follows.

In the third step, the precipitate obtained in the second step is separated, washed with water and dried by a conventional method, and the dried product is calcined at 100 ° C to 1200 ° C. When the calcination is carried out outside this temperature range, the hydrogen reduction activity and selectivity desired by the present invention cannot be obtained in the obtained catalyst.

After washing with water, the precipitate is dried by a conventional method and calcined. The firing temperature is usually in the range of 100 ° C to 1200 ° C, preferably 400 ° C to 900 ° C. The firing time is not particularly limited, but 10 hours or less is economically preferable. The product that has been calcined can be used as a catalyst immediately without crushing.

The catalyst of the present invention has excellent activity such as excellent activity and selectivity due to the combination of the above metals, but it is also possible to add other metals, for example, noble metals, etc. within a range that does not impair the effects of the present invention. , The combination of other metals is not excluded.

Hydrogen reduction of higher aliphatic ester using the above catalyst,
Temperature 130 ℃ -350 ℃, preferably 180-300 ℃, hydrogen pressure 10
~300 kg / cm ^2, preferably carried out at 100~250 kg / cm ^2. The amount of the catalyst used is in the range of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the starting higher aliphatic ester.

Examples of the higher aliphatic ester that can be hydrogenated using the catalyst of the present invention include those in which the fatty acid has 6 or more carbon atoms and one or more ester groups. As the higher fatty acid ester, either a linear aliphatic ester, a branched fatty acid ester or an unsaturated fatty acid ester may be used,
Moreover, you may use these mixtures. The alcohol constituting the higher aliphatic ester is preferably a lower alcohol having 1 to 4 carbon atoms, and particularly preferably methyl alcohol.

Specific examples of the higher aliphatic ester include coconut oil fatty acid methyl ester, palm oil fatty acid methyl ester, palm kernel oil fatty acid methyl ester, rapeseed oil fatty acid methyl ester, beef tallow fatty acid methyl ester, fish oil fatty acid methyl ester, orange raffy fatty acid methyl ester. Etc.

〔Example〕

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Production Example 1 Water (300 g), CuSO ₄ .5H was added to a reactor having a reflux condenser.
₂ O (48 g), FeSO ₄ .7H ₂ O (59 g) and aluminum hydroxide (trade name Hydilite H-32, 17.63 g) were added, and the temperature was raised to 96 ° C. with stirring. The temperature was kept at 95 ° C ± 2 ° C and kept for 1 hour.

Next, while maintaining this temperature, Na ₂ CO ₃ (44.8 g) was added to water (1
The solution dissolved in 50 g) is added dropwise over about 80 minutes. In the reaction, an initially blue-green precipitate gradually turns brown and finally becomes black. The pH after the dropping was 8.95.

While maintaining the temperature at 95 ℃ ± 2 ℃, CuSO ₄ · 5H ₂ O (4.8g) and Al ₂ (SO ₄ ) ₃ · 16H ₂ O (46.8g) dissolved in water (109.2g), A solution of Na ₂ CO ₃ (27.6 g) dissolved in water (98.2 g) was added dropwise at the same time.

The aqueous solution of the metal salt was added dropwise over 60 minutes, and the aqueous solution of the alkaline substance was added over 30 minutes. PH is 8.7 after dropping alkaline solution in water.
1. The pH after dropping the metal salt aqueous solution was 8.00.

ZnSO ₄ 5H ₂ O (3.0 g) and Al ₅ (SO ₄ ) ₃ 16H ₂ O (23.4
A solution prepared by dissolving g) in water (53.5 g) was added dropwise over 30 minutes. The pH at this time was 4.10.

Then, a solution of Na ₂ CO ₃ (15.4 g) dissolved in water (54.9 g) was added dropwise over 30 minutes. Then add 10% NaOH aqueous solution dropwise.
The pH was adjusted to 10.5. Aging was carried out for 1 hour while maintaining the pH at 10.5.

After completion of the aging, the reaction product was filtered by suction. Filtration was extremely easy and the filtrate was colorless. The precipitate was washed 3 times with 450 ml of water each time and then dried by a conventional method. The dried product was lightly crushed and calcined in air at 750 ° C. for 1 hour to obtain the desired catalyst.

The Cu / Fe / Al / Zn atomic ratio of this catalyst is 1/1 / 2.16 / 0.
It was 05.

Production Examples 2 and 3 5.86 Aluminum hydroxide (trade name Heidilite H-32)
Alternatively, a catalyst was obtained in the same manner as in Production Example 1 except that 35.2 g was used.

Production Example 4 In a reactor having a reflux condenser, water (300 g), CuSO ₄ .5H
₂ O (48 g), FeSO ₄ .7H ₂ O (59 g) and aluminum hydroxide (trade name Hydilite H-32, 17.63 g) were added, and the temperature was raised to 96 ° C. with stirring. A solution of Na ₂ CO ₃ (44.8 g) in water (150 g) was added dropwise over about 80 minutes while maintaining the temperature at 95 ° C ± 2 ° C. In the reaction, an initially blue-green precipitate gradually turns brown and finally becomes black. The pH after the dripping was 8.95.

A solution in which ZnSO ₄ 5H ₂ O (3.0 g) and Al ₂ (SO ₄ ) ₃ / 16H ₂ O (46.8 g) were dissolved in water (109.2 g) while maintaining the temperature at 95 ° C ± 2 ° C. A solution of Na ₂ CO ₃ (26.5 g) in water (94.0 g) was simultaneously added dropwise. The aqueous solution of the metal salt was added dropwise over 60 minutes, and the aqueous solution of the alkaline substance was added over 30 minutes. The pH after dropping the aqueous solution of the alkaline substance is 8.71, and the pH after dropping the aqueous solution of the metal salt is 8.
It was 00.

CuSO ₄・ 5H ₂ O (4.8g) and Al ₂ (SO ₄ ) ₃・ 16H ₂ O (23.4
A solution prepared by dissolving g) in water (53.5 g) was added dropwise over 30 minutes. The pH at this time was 4.10.

Then, a solution of Na ₂ CO ₃ (16.4 g) dissolved in water (58.2 g) was added dropwise over 30 minutes.

Thereafter, the same operation as in Production Example 1 was carried out to obtain a catalyst.

Production Examples 5 to 10 Catalysts were obtained in the same manner as in Production Example 1 except that the atomic ratio of Cu / Fe / Al / Zn was changed to the ratio shown in Table-1.

Comparative Production Examples 1 to 3 Catalysts were obtained in the same manner as in Production Example 1 except that the atomic ratio of Cu / Fe / Al / Zn was changed to the ratio shown in Table-1.

Production Example 11 Aluminum hydroxide (boehmite obtained by firing H-32 at 350 ° C for about 1 hour instead of Hydilite H-32
A catalyst was obtained in the same manner as in Production Example 1 except that 13.72 g of (AlO.OH) was used.

Production Example 12 Aluminum hydroxide (Production Example except that 14.53 g of aluminum oxide (Al ₂ O ₃ ) obtained by firing H-32 at 600 ° C. for about 1 hour instead of Hydilite H-32 was used. A catalyst was obtained in the same manner as in 1.

Production Example 13 Al ₂ (SO ₄ ) ₃ · 16H ₂ O (44 g) and NaOH (28.6 g) in water (200 g)
Were dissolved.

The solution was placed in a reactor with a reflux condenser and the temperature of the solution was raised to 100 ° C. While keeping the temperature at 100 ℃,
A solution of Al ₂ (SO ₄ ) ₃ · 16H ₂ O (26.0 g) dissolved in water (75.8 g) was added dropwise over about 2 hours.

Then, a solution of CuSO ₄ .5H ₂ O (48 g) and Fe ₂ SO ₄ .7H ₂ O (59 g) dissolved in water (150 g) is added dropwise in about 30 minutes.

The temperature of the reactor was kept at 95 ± 2 ° C. for 1 hour, and then the same operation as in Production Example 1 was carried out to obtain a catalyst.

Comparative Production Example 4 Water (400 g), CuSO ₄ .5H was added to a reactor having a reflux condenser.
₂ O (37.0 g), Fe ₂ SO ₄ / 7H ₂ O (41.3 g), Al ₂ (SO ₄ ) ₃ / 16H ₂ O
(98.3 g) and ZnSO ₄ .5H ₂ O (2.1 g) were added, and the temperature was raised to 96 ° C. with stirring. The temperature was kept at 95 ° C ± 2 ° C and kept for 1 hour.

Next, while maintaining this temperature, Na ₂ CO ₃ (88.8 g) was added to water (315
The solution dissolved in g) is added dropwise over about 80 minutes. In the reaction, an initially blue-green precipitate gradually turns brown and finally becomes black.

Further, 10% NaOH aqueous solution was added dropwise to adjust the pH to 10.5.

Thereafter, the same operation as in Production Example 1 was carried out to obtain a catalyst.

Comparative Production Example 5 Water (210 g), CuSO ₄ .5H was added to a reactor having a reflux condenser.
₂ O (33.6 g) and Fe ₂ SO ₄ .7H ₂ O (41.3 g) were added, and the temperature was raised to 96 ° C. with stirring. The temperature was kept at 95 ± 2 ° C., and kept for 1 hour.

Next, while maintaining this temperature, NaCO ₃ (31.4 g) was added to water (10
The solution dissolved in 5 g) is added dropwise over about 80 minutes. In the reaction, an initially blue-green precipitate gradually turns brown and finally becomes black.

While keeping the temperature at 95 ± 2 ℃, add CuSO ₄・ 5 into this suspension.
H ₂ O (3.4 g) and Al ₂ (SO ₄ ) ₃ · 16H ₂ O (65.5 g) were added to water (153 g).
g) and dissolved Na ₂ CO ₃ (53.2 g) in water (189 g)
The solution dissolved in was added dropwise at the same time.

Then ZnSO ₄ .5H ₂ O (2.1 g) and Al ₂ (SO ₄ ) ₃・ 16
H ₂ O (33 g) dissolved in water (74.9 g) and Na ₂ CO ₃
A solution prepared by dissolving (18.8 g) in water (66 g) was added dropwise at the same time.

After aging for 1 hour, the same operation as in Production Example 1 was performed to obtain a catalyst.

Production Examples 14 to 17 Catalysts were obtained in the same manner as in Production Example 1 except that the firing temperature was 450 ° C, 600 ° C, 900 ° C and 1050 ° C.

Test example 150 g of coconut oil fatty acid methyl ester (hereinafter referred to as ME)
3.75 g of the catalyst obtained in each Production Example and Comparative Production Example was added to a 500 ml autoclave, and the hydrogen pressure was 250 kg / cm ² ,
The reaction temperature was 275 ° C., hydrogen was flowed at 5 / min, and the reaction was carried out for 4 hours.

During the reaction, the saponification value was measured by sampling at 30, 60, 90, 120, 180 and 240 minutes.

The saponification number of the raw material ME is SV _o , the saponification number of the reaction product at the time of t minutes is SV _t , and the equilibrium saponification number at 250 kg / cm ^{2 at} 275 ° C. is SV _e. The reaction rate constant k (× 10 ³ / min) was calculated by k = (1 / t) ln (SV ₀ −SV _e / (SV _t −SV _e ), where k of the reaction was 7.2 × 10 ³ Met
(× 10 ³ is omitted in the following test examples).

After the completion of the reaction, the reaction solution was cooled, the autoclave was opened to withdraw the reaction solution, and the catalyst was removed by pressure filtration.
The composition of the obtained reaction product was analyzed by gas chromatography.

Then 150 g of ME was catalyzed to measure the filtration rate.
Add 7.50 g and hydrogen pressure 250 in 500 ml autoclave.
After carrying out the reaction for 1 hour at kg / cm ² and a reaction temperature of 275 ° C.,
The entire amount was sampled through a high-pressure valve in a state where the pressure was reduced to 200 kg / cm ² without cooling.

The extracted slurry (58 g) was weighed and diluted with dodecyl alcohol to 255 g, and then a pressure filter with an internal heating temperature control of 3 cm inner diameter was used under constant conditions (filtering pressure 3 kg / cm ² , filtration). Filtration was performed at a temperature of 50 ° C.), and a filtration rate constant F (m ³ / m ² −Hr) per unit time was obtained.

The results are shown in Table-1.

EFFECTS OF THE INVENTION According to the present invention, a copper-iron-aluminum-zinc-based catalyst having extremely high activity and high selectivity can be obtained, and by using such a catalyst, a very high purity higher alcohol can be very easily obtained. can get.

Claims (1)

[Claims] 1. A carrier comprising aluminum hydroxide or aluminum oxide or a mixture thereof, containing Cu, Fe, Al and Zn, and having an atomic ratio (atomic ratio of the entire catalyst including the carrier) of Cu / Fe.
/Al=1/0.4 to 2.5 / 0.5 to 5.0 and Zn / Cu ≦
Catalyst for alcohol production by hydrogenation of fatty acid ester which is 1.0.